Toshiba RAS-M10YKV-E Service Manual page 47

Tightening connection
Align the centers of the connecting pipes and
tighten the flare nut as far as possible with your
fingers. Then tighten the nut with a spanner and
torque wrench as shown in the figure.
CAUTION
• Do not apply excess torque. Otherwise,
the nut may crack depending on the
conditions.
(Unit : N·m)
Outer dia. of copper pipe Tightening torque
ø6,35 mm 14 to 18 (1,4 to 1,8 kgf•m)
ø9,52 mm 33 to 42 (3,3 to 4,2 kgf•m)
ø12,7 mm 50 to 62 (5,0 to 6,2 kgf•m)
• Tightening torque of flare pipe connections
Pressure of R410A becomes higher than that
of R22. (Approx. 1,6 times) Therefore, using a
torque wrench, tighten firmly the flare pipe
connecting sections which connect the indoor
and outdoor units up to the specified
tightening torque. Incorrect connections may
cause not only a gas leakage,
but also a trouble of the refrigeration cycle.
Flare at
indoor
unit side
Flare at
outdoor
unit side
Fig. 9-3-10
Never apply refrigerating machine oil to
the flare surface.
Half union
Flare nut
Externally Internally
threaded side threaded side
Use a wrench to secure. Use a torque wrench to tighten.
ø6,35
B B UNIT
ø9,52
ø6,35
A A UNIT
ø9,52
Indoor unit
Outdoor unit
Fig. 9-3-11
9-3-8. Evacuating
After the piping has been connected to all indoor
unit(s), you can perform the air purge together at
once.
AIR PURGE
Evacuate the air in the connecting pipes and
in the indoor unit using vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the manual of vacuum pump.
Use a vacuum pump
Be sure to use a vacuum pump with counter-flow
prevention function so that inside oil of the pump
does not flow backward into pipes of the air
conditioner when the pump stops. (If inside oil of
the vacuum pump enters into the air conditioner
which adopts R410A, a trouble of the refrigeration
cycle may be caused.)
1. Connect the charge hose from the manifold
valve to the service port of the gas side
packed valve.
2. Connect the charge hose to the port of
vacuum pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to start for
evacuating.
Perform evacuating for about 15 minutes if the
total piping length is 30 meters. (15 minutes
for 30 meters) (assuming a pump capacity of
27 liters per minute.)
Then confirm that the pressure gauge reading
is –101 kPa ( –76 cmHg).
5. Close the low pressure side valve handle of
gauge manifold.
6. Open fully the valve stem of the packed
valves (both side of Gas and Liquid).
7. Remove the charging hose from the service
port.
8. Securely tighten the caps on the packed valves.
9. Execute above works from 1 to 8 on the each
connected indoor unit.
Compound pressure gauge Pressure gauge
–101kPa (–76cmHg)
Manifold valve
Handle Lo
Handle Hi
(Keep full closed)
Charge hose
(For R410A only) Charge hose
(For R410A only)
Connecting
pipe Vacuum pump adapter
for counter-flow prevention
(For R410A only)
Vacuum
pump
Packed valve at liquid side
Packed valve at gas side
Service port
(Valve core (Setting pin))
Fig. 9-3-12
Packed valve handling precautions
• Open the valve stem all the way out; so not try
to open it beyond the stopper.
• Securely tighten the valve stem cap torque is
as follows :
Gas side 50 to 62 N•m
(ø12,7 mm) (5,0 to 6,2 kgf•m)
Gas side 33 to 42 N•m
(ø9,52 mm) (3,3 to 4,2 kgf•m)
Liquid side 14 to 18 N•m
(ø6,35 mm) (1,4 to 1,8 kgf•m)
14 to 18 N•m
Service port
(1,4 to 1,8 kgf•m)
Hexagon wrench is required.
Fig. 9-3-13
9-3-9. Electrical Work
For the air conditioner that has no power cord,
connect a power cord to it as mentioned below.
Maximum
Power Fuse Power
running
source rating cord
current
220–230–240 2,0mm
Single phase 8,5 A 10A (AWG-14)
50 Hz or more
Terminal block Terminal block
(Power supply) (Connecting cable)
Earth line
Screw Cord clamp
Connecting cable
Power cord
(B unit)
Connecting cable
(A unit)
Fig. 9-3-14
How to wiring connection
1. Connect the connecting cable to the terminal
as identified with their respective matched
numbers on the terminal block of indoor and
2
outdoor unit. (1,0 mm AWG 18 or more)
2. When connecting the connecting cable to the
outdoor unit terminal, prevent water coming in
the outdoor unit.
3. Insulate the unused cords (conductors) with
strip the sheath of connecting cable with PVC
tape.
Process them so that they do not touch any
electrical or metal parts.
4. For inter-unit wiring, do not use a cut wire
jointed to another on the way.
Use wires long enough to cover the entire
length.
CAUTION
• Wrong wiring connection may cause some
electrical parts burn out.
• Be sure to use the cord clamps specified
positions with attached to the product.
• Do not damage or scratch the conductive
core and inner insulator of power and inter-
connecting cables when peeling them.
• Be sure to comply with local codes on
running the wire from outdoor unit to indoor
unit (size of wire and wiring method etc.)
• Use the power cord and Inter-connecting
cable with specified thickness, specified
type, and protective devices specified.
2
Stripping length power cord and
connecting cable
10
L N 1 2 3
10 10
40
30 30
Earth line
Power cord
Fig. 9-3-15
10
40
Earth line
Connecting
cable